I've been doing lots of plumbing this week. All the new lines I ran with PEX - which is awesome and I definitely recommend it. So when I go to tie in to my existing 1/2" copper water lines, I find that the pipes are no longer the diameter of standard 1/2" tubing. Previous freezing, or just plain old age has increased the size to some non-standard dimension that there is no off-the-shelf fitting for. What to do?

Obviously the answer is to make your own custom sized fittings, but the trick was to find the best way to do it. So here's what you do: as the picture suggests, flare out standard 1/2" couplings to fit the expanded pipes. I used metric sockets and a hammer (one of the few times that a hammer will solve a plumbing problem..lol). Since sockets are much harder than coppper and plated to begin with, they work pretty well. Voila! The flared couplers soldered well to the existing pipes and allowed the use of normal 1/2" stuff from there out.